A role for Vibrio vulnificus PecS during hypoxia
A role for Vibrio vulnificus PecS during hypoxia
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DOI：
10.1038/s41598-019-39095-4
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发表时间：
2019-02-26
影响因子：
4.6
通讯作者：
Grove, Anne
中科院分区：
文献类型：
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作者：
Bhattacharyya, Nabanita;Lemon, Tiffany L.;Grove, Anne
弧菌属包括严重的人类病原体，软体动物是创伤弧菌等物种的重要储存库。弧菌编码多重抗生素耐药调节因子（MarR）家族成员PecS；pecS向pecM发散，pecM编码一个外排泵。我们在这里报道，弧菌物种具有频繁的pecS-pecM基因重复，表明进化压力以应对不同的环境情况。单一的创伤弧菌PecS结合PecS - pecm基因间区的两个位点，K-d = 0.3 +/- 0.1 nM，这种结合被黄嘌呤和尿酸盐配体减弱，除非启动子DNA被PecS饱和。在编码一氧化氮传感转录因子NsrR和nod的基因之间的基因间区域发现了一个独特的靶点；节点编码的一氧化氮双加氧酶在预防一氧化氮应激中起重要作用。报告基因实验表明，配体的存在可以缓解pecs介导的基因表达抑制。由于黄嘌呤和尿酸盐是在宿主防御和软体动物缺氧时作为氧化爆发的一部分产生的，我们认为这些宿主嘌呤降解途径中的中间体在缺氧和氧化应激下促进细菌存活。
The genus Vibrio includes serious human pathogens, and mollusks are a significant reservoir for species such as V. vulnificus. Vibrio species encode PecS, a member of the multiple antibiotic resistance regulator (MarR) family of transcription factors; pecS is divergently oriented to pecM, which encodes an efflux pump. We report here that Vibrio species feature frequent duplications of pecS-pecM genes, suggesting evolutionary pressures to respond to distinct environmental situations. The single V. vulnificus PecS binds two sites within the pecS-pecM intergenic region with K-d = 0.3 +/- 0.1 nM, a binding that is attenuated by the ligands xanthine and urate, except when promoter DNA is saturated with PecS. A unique target is found in the intergenic region between genes encoding the nitric oxide sensing transcription factor, NsrR, and nod; the nod-encoded nitric oxide dioxygenase is important for preventing nitric oxide stress. Reporter gene assays show that PecS-mediated repression of gene expression can be relieved in presence of ligand. Since xanthine and urate are produced as part of the oxidative burst during host defenses and under molluscan hypoxia, we propose that these intermediates in the host purine degradation pathway function to promote bacterial survival during hypoxia and oxidative stress.